Chair arm



FIG. 1 is a perspective view showing the front, top and left side of a chair arm which forms my new design, the broken lines in this and other figures being for illustrative purposes and forming no part of my design;

FIG. 2 is a left side elevational view thereof;

FIG. 3 is a right side elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a front elevational view thereof; and,

FIG. 6 is a top plan view thereof. 

The ornamental design for a chair arm, as shown and described. 